I just recently purchased and started playing GalCiv2 Ultimate, and one thing I have noticed that is a bit "user-unfriendly" about the user interface is the selection of sort order for the planet and ship lists.

I think I counted a total of 37 different sort options for the planet list, and 26 for the ship list, and you need to repeatedly click to go from one to the other.  If you have managed to memorize the order, it could take as much as 18 clicks to get from one sort order to the one you want, and if, as is more likely, you haven't memorized the order, you may start going in the wrong direction and have to click up to 35 times to find the one you want.

This would seem an ideal location to offer either a drop-down or popup selector to choose the desired sorting.  The easiest way for the developers to add this feature might be to have the user double-click or right-click on the control to provide the list selector, since single-click is already used to reverse the sort order.  The other option would be to add a traditional drop-down arrow control on the right side, but that may require layout changes in the UI for space reasons, and would therefore probably be more work to implement.

Also, I think there are some other places in the UI where a similar selector is used, so anywhere where more than 4 or 5 choices need to be clicked through, it would be good to also use a similar method.  However, I would guess that most likely, a standard UI component is used throughout the interface, so if it was updated for the sort lists it would automatically carry through to the other various screens.